An Inquiry into Meaning and Truth examines the relation between our language and the world. Russell talks about the hierarchy of empirical knowledge, consisting of the facts, observed or unobserved, the basic propositions, and the inferred propositions. On the epistemological side he is a foundationalist. The reason to believe any empirical sentence is one or more other sentences, we already believe, "or some non-linguistic occurrence having a certain relation to the sentence believed" (p. 226). Ontologically he thinks of the objects as a bundle of properties: " a »thing« is nothing but a bundle of coexisting qualities" (p. 97). His reason is, only by this way, one can stick to the principle of the identity of indiscernibles. Finally, Russell's theory of truth is a correspondence between basic propositions and some occurrence in the world.